Narrative:

Approach to torrance, ca, on assigned heading off V-459 at 8000 ft. 'Electrical malfunction.' initial condition #1. Battery overheat warning light illuminated. Pilot response a. Both batteries switched off via common switch. Condition #2. Battery overheat light illuminated and #1 began to flash. Response B: both generators taken offline resulting in engines to increase from 96% to 100 % as computers dropped off and manual mode overspd governors checked engine speed. Autoplt offline. Communication lost and navigation lost, but not require because VFR. Response C: put #1 generator back on line, pushed autoplt, but lost communication frequency. Autoplt out of trim -- lost 1000 ft prior to catching problem with attention diverted to lost communication and engine management. Regained 8000 ft in approximately 12 to 15 seconds from noticing problem and tried autoplt 1 more time, again losing altitude but loss limited to 400 ft and autoplt circuit breaker pulled. Communication re-established with coast approach as per approach plate frequency and landed without further incident. Series of problems started by a runaway nicad battery with reversed cells. Pilot failed to catch altitude hold and trim problems with preoccupation of possible fire and lost communication. Pilot did not have frequencys written down for back up.

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Original NASA ASRS Text

Title: PLT OF SMT PRIVATE ACFT EXPERIENCED AN ELECTRICAL MALFUNCTION RESULTING IN EXCURSION FROM ASSIGNED ALT.

Narrative: APCH TO TORRANCE, CA, ON ASSIGNED HDG OFF V-459 AT 8000 FT. 'ELECTRICAL MALFUNCTION.' INITIAL CONDITION #1. BATTERY OVERHEAT WARNING LIGHT ILLUMINATED. PLT RESPONSE A. BOTH BATTERIES SWITCHED OFF VIA COMMON SWITCH. CONDITION #2. BATTERY OVERHEAT LIGHT ILLUMINATED AND #1 BEGAN TO FLASH. RESPONSE B: BOTH GENERATORS TAKEN OFFLINE RESULTING IN ENGS TO INCREASE FROM 96% TO 100 % AS COMPUTERS DROPPED OFF AND MANUAL MODE OVERSPD GOVERNORS CHKED ENG SPD. AUTOPLT OFFLINE. COM LOST AND NAV LOST, BUT NOT REQUIRE BECAUSE VFR. RESPONSE C: PUT #1 GENERATOR BACK ON LINE, PUSHED AUTOPLT, BUT LOST COM FREQ. AUTOPLT OUT OF TRIM -- LOST 1000 FT PRIOR TO CATCHING PROBLEM WITH ATTN DIVERTED TO LOST COM AND ENG MGMNT. REGAINED 8000 FT IN APPROX 12 TO 15 SECONDS FROM NOTICING PROBLEM AND TRIED AUTOPLT 1 MORE TIME, AGAIN LOSING ALT BUT LOSS LIMITED TO 400 FT AND AUTOPLT CIRCUIT BREAKER PULLED. COM RE-ESTABLISHED WITH COAST APCH AS PER APCH PLATE FREQ AND LANDED WITHOUT FURTHER INCIDENT. SERIES OF PROBLEMS STARTED BY A RUNAWAY NICAD BATTERY WITH REVERSED CELLS. PLT FAILED TO CATCH ALT HOLD AND TRIM PROBLEMS WITH PREOCCUPATION OF POSSIBLE FIRE AND LOST COM. PLT DID NOT HAVE FREQS WRITTEN DOWN FOR BACK UP.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.